Let $f(x)=-19e^x$. $f'(x)=$
Answer: Recall that ${\dfrac{d}{dx}[e^x]=e^x}$. $\begin{aligned} h'(x)&=\dfrac{d}{dx}[-19e^x] \\\\ &=-19{\dfrac{d}{dx}[e^x]} \\\\ &=-19{e^x} \end{aligned}$ In conclusion, $f'(x)=-19e^x$